MiG-29's BFM characteristics / doubts

It is not a certain plane and certain weight diagram, it is a general diagram showing the main general laws for any modern fighter. It can be derived from Su-27, MiG-29, F-15, F-18, whatever, but the main dependancies will be the same. Only the certain numbers can vary a bit.

Oh I see.

Is it possible to get the diagram (with ROT insteag of Gs) for the MiG-29 anywhere ?

Thank you.

If the formulas are not obvious.

 

So, few rules consequent from the math:

instant turn radius is CONSTANT within useful speed range until g-limit is reached;

AB and MIL sustained turn rate generally increases with speed up to transsonic range with higher drag losses;

sustained turn radius generally increases with speed for AB though low speed MIL turn can have almost constant radius at low speed.

Hi Yo-yo,

is performance line for max AoA, or...? What "state" is the aircraft in when getting these results (red/blue lines)?

Oh I see.

Is it possible to get the diagram (with ROT insteag of Gs) for the MiG-29 anywhere ?

 

Thank you.

I am planning on doing flight tests in DCS and will post the results here.

I am planning on doing flight tests in DCS and will post the results here.

Glad to know it!

Let me just show part of my 'testing' on the MiG-29's capabilities regarding Instantaneous Turn Rate.

As the 28 deg / sec mentioned throughout several places in the web isn't its absolute maximum ITR... sure was VERY low on fuel, and also a clean config, but managed 30.4 deg / sec.

Airspeeds in kph.

...

Let me just show part of my 'testing' on the MiG-29's capabilities regarding Instantaneous Turn Rate....

How do you get all that data to be displayed in the label in TacView?

How do you get all that data to be displayed in the label in TacView?

I'm still a newbie in tacview, but like in the image below:

- you click the symbol in the red circle (bottom of the screen)

- then "select objects labels"

- and in the next list, you select the data you want.

- for changing the type of units in data, you select the symbol in green circle - top of the screen.

You must keep the cursor over the aircraft to the data keep showing.

Also the aircraft symbol (green circle in the bottom) must be selected.

Glad to know it!

 

Let me just show part of my 'testing' on the MiG-29's capabilities regarding Instantaneous Turn Rate.

 

As the 28 deg / sec mentioned throughout several places in the web isn't its absolute maximum ITR... sure was VERY low on fuel, and also a clean config, but managed 30.4 deg / sec.

 

Airspeeds in kph.

AHA! So that's where they get it. I always wondered what kind of magic people were working to get those numbers. I was like ''surely they're not using a stopwatch''.

I don't use TacView much. Obviously.

AHA! So that's where they get it. I always wondered what kind of magic people were working to get those numbers. I was like ''surely they're not using a stopwatch''.

 

I don't use TacView much. Obviously.

Believe it or not, I am using a stop-watch :doh:

Believe it or not, I am using a stop-watch :doh:

Yeaaah... probably a little more susceptible to rounding errors that way :lol:

I'm still a newbie in tacview, but like in the image below:

 

- you click the symbol in the red circle (bottom of the screen)

- then "select objects labels"

- and in the next list, you select the data you want.

 

- for changing the type of units in data, you select the symbol in green circle - top of the screen.

 

You must keep the cursor over the aircraft to the data keep showing.

Also the aircraft symbol (green circle in the bottom) must be selected.

I tend to like the graphs better for view states over time:

I tend to like the graphs better for view states over time:

Didn't get there yet.

Still those seem to be Sustained turn rates, yes?

You can see it in the ED newsletter few weeks ago. Though the diagrams are presented in G terms, they easily can be converted to turn rate or turn radius using trivial math.

Sorry, newsletter ?

Didn't know it.

Can't find it at all.

You mean this:

https://forums.eagle.ru/showthread.php?t=151478&page=27

https://www.digitalcombatsimulator.com/en/news/dcs_a_10c_warthog_released/downloads/downloads/screenshots/en/myserials.php

Didn't get there yet.

Still those seem to be Sustained turn rates, yes?

Yes and no. I didn’t put up the third graph which might have helped explained it a bit.

Starting from straight line flight, roll, and smoothly pull stick back adjusting throttle as necessary to slowly lose speed in a level (more or less) turn to allow Gs to build. Continue to hold stick full back as you pass thru max-G and, then, ride it further as the speed continues to decay. The ITR isn’t as high as it would be with a quick stick pull but it’s there along with the abrupt speed drop.

Just interesting to see what’s happening.

Edit: Forgot to mention. Altitude was around 150-200 meters.

Sorry, newsletter ?

Didn't know it.

 

Can't find it at all.

You mean this:

 

https://forums.eagle.ru/showthread.php?t=151478&page=27

 

https://www.digitalcombatsimulator.com/en/news/dcs_a_10c_warthog_released/downloads/downloads/screenshots/en/myserials.php

You’re looking for the flight modeling paper

You’re looking for the flight modeling paper

Hello

Sorry, but I still don't have the slightest idea of where are those documents, or where is the "newsletter" @Yo-Yo mentioned.

Yes and no. I didn’t put up the third graph which might have helped explained it a bit.

 

Starting from straight line flight, roll, and smoothly pull stick back adjusting throttle as necessary to slowly lose speed in a level (more or less) turn to allow Gs to build. Continue to hold stick full back as you pass thru max-G and, then, ride it further as the speed continues to decay. The ITR isn’t as high as it would be with a quick stick pull but it’s there along with the abrupt speed drop.

 

...

 

Just interesting to see what’s happening.

 

Edit: Forgot to mention. Altitude was around 150-200 meters.

Thank you for the insight.

In bold, that's the only way I could get those 30.4 deg/sec ITR in the MiG - quick pull.

Didn't try very much with the Su-27 for Tacview, but I suspect that it would achieve even higher ITR than the MiG-29.

But tested it enough to get the impression, that the Flanker can even maintain a slightly smaller Turn Radius tha the Fulcrum.

(Roughly 280m at 300 kph for the Flanker, vs 300m at 320 kph for the MiG.)

Also, I've tested just a little the F-14B in Tacview, and let me just tell you (something that you already know from long ago):

In DCS, the amount of pure G force the Tomcat can employ at around 330 kts (clean config, sea level)... does give it such a Sustained Turn Rate, that the Fulcrum and probably the Flanker can only be envious of.

I mean, sometimes one starts to think: " maybe the papers are inverted ? "... even the F-15C feels more maneuverable than the MiG-29 in several aspects.

Man... does the Fulcrum have any card up its sleeve after all ?

I mean, in gone times (~the 90's) it was referred to as: "probably the world's most lethal dogfighter" and such... but in DCS against other types, frequently I really don't get that feeling.

Looking at it in DCS, I must admit it sure is a far cry from the very first impressions I got on it, long ago:

- "TOPGUN: Fire AT Will!" for PC, circa 1995 ;

- ok, I'm fully aware that its flight model realism was "debatable", bearing in mind its time ;

- the F-14 Tomcat featured was probably the "A" version with the underpowered TF-30 engines ;

- the enemy Su-27s never appeared that much maneuverable, as I imagine they came full on internal fuel, since supposedly according to the script these types were frequently employed in long range flights, allied bomber interception, anti-ship attack, etc.

... but the MiG-29, that was indeed something else... frequently flown by bogeys to directly confront my Tomcat; also flown by the main vilain, and in every situation - with an astonishing Sustained Turn Rate and also a perceptibly small turn radius, causing a dogfight with him to be extremelly difficult to win in the Tomcat.

Then one beggins to test the MiG thoroughly in DCS, and it does look somewhat...wihtout that much dangerous capability.

Thank you for the insight.

In bold, that's the only way I could get those 30.4 deg/sec ITR in the MiG - quick pull.

 

...

In another quick flight last night similar to the one from the graphs above, I hit 30.0°/sec ITR without a quick pull. Turn radius was right around 400 m at that point. The difference between the two was gross weight. I was on fumes this time. In the previous flight I was somewhere between 1000 and 2000 kg heavier.

...

 

Man... does the Fulcrum have any card up its sleeve after all ?

I mean, in gone times (~the 90's) it was referred to as: "probably the world's most lethal dogfighter" and such... but in DCS against other types, frequently I really don't get that feeling.

 

Looking at it in DCS, I must admit it sure is a far cry from the very first impressions I got on it, long ago:

 

...

 

Then one beggins to test the MiG thoroughly in DCS, and it does look somewhat...wihtout that much dangerous capability.

Much of it's aclaim, I believe, came from its off boresight capabilities. In the early days, no other aircraft could launch a missile in your direction while its nose was pointed so far away from you. It's ok in a fight as long as you keep the speed up.

You can see it in the ED newsletter few weeks ago. Though the diagrams are presented in G terms, they easily can be converted to turn rate or turn radius using trivial math.

How exactly

https://forums.eagle.ru/showthread.php?t=281651

 

Sorry, misleaded a bit.

Thank you !

Results of a study of the Mig 29 model from the DCS by aerodynamic specialists from the "Mig" corporation.

Итак, то, о чем нам так долго говорили большевики, в смысле аэродинамики, подтвердилось в очередной раз. А именно то, что расчетные методы пока еще очень далеки от совершенства. К сожалению. Потому что из этого следует старый и очень простой вывод: надо дуть, а не заниматься расчетами, а это, к сожалению, очень и очень дорого. Если честно, то где-то в душе я надеялся, что расчет совпадет с практикой, но нет, не совпал. Это я про тот документ, который в ЕД гордо называют "продувками". Давайте все же договоримся не называть это продувками, это самый обычный расчет.

Теперь по сути. Аэродинамикам была поставлена задача потратить время на изучение упомянутого расчета в части характеристик при влиянии земли, оценить полученный в расчете результат и качественно, но не количественно, сравнить с имеющимися в их распоряжении данными продувок и летных испытаний. Не буду говорить те слова, которые я услышал на счет материала представленного в целом, скажу по сути. То, что касается представленных расчетных данных в условиях IGE (то бишь с влиянием земли), очень сильно не совпало с реальными продувками, причем с самого начала, что называется от печки. Местами в разы. Не совпали моменты, не совпали характеристики стабилизатора.

Так что говорить, что что-то там опровергнуто с помощью CFD не стоит. Во всяком случае в ближайшие лет 10. Потом люди наверняка научатся считать такие вещи правильно, но пока - нет. Именно поэтому настоящие аэродинамики используют результаты CFD крайне осторожно и ограничено. Причем для разных случаев используют разные методы и разные программные комплексы ибо работают они по-разному, где-то один ближе, где-то другой. Но эти случаи всегда изначально продуты, и проведена оценка сходимости расчета с реальным экспериментом.

На счет того, что кто-то когда-то снимал балансировки в условиях IGE - повторюсь, в летных экспериментах этого никто не делал, не делает и делать не собирается, ибо бесполезно. А над вопросом откуда графики берутся в ПА предлагаю думать самостоятельно.

Ну и вывод: модель полета МиГ-29, представленная в DCS на взлете и посадке при влиянии земли не соответствует тому, что наблюдается в реальной жизни, о чем, собственно, на этом форуме неоднократно говорили очень многие.

Как-то так...

Interesting find Flanker

How about the Authenticity of the Su-27/33 FM in DCS?

How close or far is it from the real thing

That's another example of unprofessional and biased opinion, I hope that the English forum members with aero-engineering background can explain you the graph below (MiG-29 AB trim at low altitude from our newsletter) if you can not understand it yourself and prefer to amplify somebody's statement...

There is not much to understand.

I'm not interested in the area above M0.4 and also the last sec before touchdown ground effect at an altitude of 0.5m no longer interests me. You know it very well. But let's not go back here to figure 8.9. or better to say, your "homemade" graphic interpretation of it again and again....

As I said, pure demagogy

The English forum members with aero-engineering background unfortunately do not read the russian threads.

I'm just waiting for yours

подкрутим.